PASADENA, Calif.--(BUSINESS WIRE)--Arrowhead Research Corporation (NASDAQ: ARWR), a targeted therapeutics company, today announced that it has received a Notice of Allowance from the U.S. Patent and Trademark Office for U.S. Patent Application Number 13/336,028 entitled, “In Vivo Polynucleotide Delivery Conjugates Having Enzyme Sensitive Linkages.” This new IP expands the Dynamic Polyconjugate (DPC) platform, broadly protecting Arrowhead’s next generation DPC polymer masking technology. Using this masking technology, DPCs can be engineered for long circulation times and improved tissue-targeting characteristics. In addition, hepatocyte-targeted DPCs formulated using this new masking technology have shown to be highly potent upon subcutaneous administration. The company has previously reported target gene knockdown of 99% in monkeys after a single subcutaneous injection of 1 mg/kg, with >80% knockdown for 3 months. Additional data will be reported at upcoming scientific conferences and through peer-reviewed publications.